Allergen Association

People With Allergies May Have Lower Risk of Brain Tumors

An Ohio State University study adds to growing evidence that links allergies and reduced risk of a type of brain cancer. The study suggests the reduced risk is stronger among women than men, but men with certain allergy profiles also have a lower tumor risk.

Because these tumors, called gliomas, can suppress the immune system to allow themselves to grow, researchers have never been sure whether allergies reduce cancer risk or if, before diagnosis, these tumors interfere with the hypersensitive immune response to allergens.

In this study, scientists analyzed stored blood samples taken from patients decades before they were diagnosed with glioma. Men and women whose blood samples contained allergy-related antibodies had an almost 50-percent lower risk of developing glioma 20 years later compared with people without signs of allergies.

“This is our most important finding,” says Judith Schwartzbaum, PhD, a member of the OSUCCC – James Cancer Control Program and the study’s lead author. “The longer before glioma diagnosis that the effect of allergies is present, the less likely it is that the tumor is suppressing allergies.”

The researchers analyzed stored blood samples from 594 people in Norway who were diagnosed with glioma (including 374 with glioblastoma) from 1974-2007, then compared them – for date of blood collection, age and sex – with 1,177 samples from people not diagnosed with glioma.

They next measured levels of two types of proteins called IgE, or immunoglobulin E – antibodies produced by white blood cells that mediate immune responses to allergens. In each sample, they determined whether the serum contained elevated levels of IgE specific to common allergens in Norway, as well as total IgE.

Among women, testing positive for elevated allergen-specific IgE was associated with a 54-percent decreased risk of glioblastoma compared with women who tested negative for allergen-specific IgE. The researchers did not see this association in men.

“There is definitely a difference in the effect of allergen-specific IgE between men and women,” Schwartzbaum says.